Heat control system



Nv l3,1941@ F. A. Gum-HER 2,301,040

HEAT CONTROL SYSTEM Filed Oct. 2, 1939 felix ,4. Gunther `is disclosed in my `quiring that Patented Nov.'3, 1942 UNITED STATESHPATENT OFFICE HEAT CONTROL SYSTEM Felix A. Gunther,

Pittsburgh, Pa., assigner to Bocjl Corporation, Pittsburgh, Pa., a corpora-` tion of Delaware 13 Claims.

Afor buildings and is for a control system particularly applicable for use with heat control apparatus of the type wherein an outdoor temperature-responsive element cooperates with a prom `gram cam which is clock-driven for periodically `turning the heat on and off for periods of irregular duration according'to fluctuations in the outside temperature. Such type of outdoor control copending application Serial No. 756,966, led January 11i, 1934, now issuedV as Patent No. 2,174,558.

In the adaptation of heat control devices of the type referred to and as disclosed in my said application, it is intended that such systems find` their greatest application to large buildings, particularly ofice buildings. rJlhe heating systems in large buildings such as large oflice buildings are usually divided into a number of zones, each zone supplying heat to a given portion of the building. While it is possible to simultaneously control alllof the Zones from a single automatic heat control unit, it is preferable to group sev- `eral Zones into a section covering a considerable part of the Whole building, and have an auto-` matic control panel for each section or group. This is because different parts of the same building are simultaneously subjected to different outdoor temperature conditions, as exposure to sun,

Wind or proximity of neighboring buildings. As

a specific example, in a square building there .j

might be four control panels, one covering all of the zones in the east side of the building, another south, etc. Such a grouping of zones into sec- -tions provides ilexibility of control Without rethere be a separate automatic control panel for each individual zone.

The present invention enables a single control unit to govern the heating program of a number of zones. Heating systems of this character are adapted to heat the building in accordance with a pre-arranged program or schedule. For example, in an oilice building the heat is turned on and orf during the day a sucient number of times and for periods of suilicient duration to maintain an average room temperature of approximately 72; During the night, say from 6 ocloek in the evening until 6 oclock in the morning the program cam allows the average temperature to drop to say about 65D and from 6 A. M. until perhaps 7:30 there is a heating up period to bring the building temperature up to around 72. It frequently happens in an oice building that certain oiiices are occupied during the evening or night so that the heat has to be main- Lro tained at the higher temperature of around 72 and of course it cannot be predicted Which olices will require heat over a longer period and will be occupied at night and when they Will be so occupied.

The purpose of the present invention is to provide a system of control which will maintain the regular program established for the building in all of the several Zones Which it controls but wherein a great ilexibility is provided in enabling any one Zone to be supplied with heat according to its requirements at any time. For example, when a'given suite of oiiices is to be occupied at night, the p-resent system enables one Zone or any selected zones to be operated on day schedule While the remaining 4zones are operating on the night schedule all under the operation of a single control unit which enables any zone to be immediately operated independently of the other zones and Without reference to the program cam at all. The system further provides that when Va tenant enters the building after the night program has been established, heat can be instantly supplied'to the zone in which his oflice is located `entirely independently of Whether-the control system may at that particular instant be in a period where the steam is off or on. v

It also hap-pens that one or more zones out of several that are subject to control from a single control unit cool off more rapidly than other Zones in the same building under the same control unit or there may be insufficient radiation in some zones or defective piping. The present sys` tem will, because of one or more zones maintaining inadequate temperatures While other zones subject to the same control are adequately supplied, aid in revealing which zones are defective in any of these respects and enable the lbuilding manager to take care of the defect and also enable heat to be supplied at a greater rate to any such Zone while the other zones under control of the same unit operate according to the program.

In brief, the present system provides a system of mechanical control wherein a single outdoorindoor unit will normally control a number of heating zones according to a pre-arranged program but wherein any particular zone may be operated contrary to the program and according to the requirements of the occupants of the building at any time Without taking the other zones off the program and according to which any unusual or irregular condition in any one zone can be compensated for. The invention may be more fully understood with reference to the accompanying drawing which illustrates a present and preferred embodiment of my invention and in which the gure is a diagrammatic View of the circuits and apparatus comprising my invention.

In the drawing the entire heating system of course has not been shown, as the invention resides in the controls and not in the heating system per se. Consequently in the drawing I have shown only the valves for controlling the admission of steam to the separate zones. Moreover, I have illustrated only two valves and the accompanying control circuits, but there may be any number of valves controlled from a single control unit. For the purpose of simplicity only two have been shown. Additional valves for additional zones would require only the duplication of the circuits illustrated or the extension of the circuits illustrated in the manner which is obvious to those skilled in the art. Two valves are sufficient to illustrate the principle of ileXibility of control provided by the invention.

In the drawing, A and A represent two valves or other sources of heat. They are each provided with inlet pipes B and B' that may be manifolded to a single supply main not illustrated. Each is illustrated as having outlet pipes C and C respectively which carry the steam to the separate heating systems or zones of a building. A small building might. have only a single valve A and the heating system may not be divided into Zones at all, whereas a large building may have as many as 40 or more Zones each of which would have its own valve A. For the purpose of the present invention, each of the valve units A and A may be considered as having a separate mechanism schematically illustrated at D and D' respectively corresponding to that illustrated in Figure 9 of the drawing of my said copending application. For the purpose of more clearly understanding the circuits, it may be pointed out that each valve has a valve element with a valve stem that is reciprocated by a cam. As explained in my said copending application, the cam is on a shaft which is driven always in the same direction, and when the high part of the cam is in one position, the valve is closed and when the high part of the cam is 180 opposite, the valve is open. An electric motor drives the cam shaft through a reducing gear, and there are three control cams on the cam shaft for governing the operation of the motor. One of these is called a circuit-maintaining cam which opens a switch to supply current to the motor when the valve is either open or closed but which supplies current to the motor while the cam shaft is being rotated to move the valve from the open to the closed position or vice versa. A second cam-operated switch is designated the on cam switch. This cam serves to close a switch when the valve is closed and the next operation to be performed is to turn the heat on. It is so arranged that it supplies current to the motor only to initiate the operation of the motor until the maintaining switch is closed. A third switch operated from this cam shaft is the oli switch. This switch is closed at the time the valve is open and the steam is turned on and when the next operation to be performed is to close the valve to turn oiT the heat. It is 180 out-of-phase with the on cam switch and like the on cam switch it opens after the operation of the driving motor has been initiated and the maintaining switch is closed to continue to operate the valve to the closed position. It will therefore be seen that the maintaining switch is open when the valve is either fully opened or fully closed, and serves to supply current to the motor after the operation of the motor has been initiated to move the valve from one position to the other. The on and off cams are 186 out-of-phase and the on cam closes a switch when the valve is closed and the heat is turned off and the off cam closes a switch when the heat is turned on.

In the drawing, terminal I on each cam valve control unit D leads to the on switch. Terminal 2 leads to the ofi switch. Terminal 3 leads to the maintaining cam, and terminal 4 is the common return side or contact for each of the other three switches.

All of the rest of the apparatus in the circuit illustrated has to do with the wires leading to the terminals I, 2, 3, and 4.

The control apparatus comprises a time switch T for changing the control circuit from the day program to the night program and from the night program to the day program according to a predetermined schedule. This in turn controls the operation of a day relay designated generally as 5 and a night relay designated generally as S. E designates a switch control panel for valve A and E is a switch control panel for valve A. The automatic temperature-responsive heat control apparatus more or less schematically illustrated at F corresponds to' the control apparatus disclosed in my said copending application. The control unit F includes two motordriven cam devices of which F1 governs the heating-up and day schedule of operation and F2 establishes or maintains the normal night schedule of operation. In conjunction with the day cam unit F1 is an indoor thermostat hereinafter called the day thermostat designated G1, and there is a similar indoor thermostat G2 in circuit with the night cam unit F2.

Referring rst to the control unit designated generally as F, the day cam unit F1 comprises an electrically driven clocl; I) which rotates a heat control cam II. The cam I I and its construction preferably correspond to the construction described in detail in my said copending application. This cam cooperates with a pivoted arm I2 which arm is moved toward and from the center ci" the cam II through a link I3 operated from a temperature-responsive element or thermostat I/l. The temperature-responsive element or thermostat is illustrated as being of the type wherein there is an outdoor bulb I5 positioned on the outside of the building whose temperature is to be controlled, the arrangement being such that as the outdoor temperature falls, the arm I2 is caused to move in toward the center of the cam II and as the temperature rises, the arm I2 moves toward the periphery of the cam II. The arm I2 is of a resilient character. When the cam II passes under the terminal of the arm I2, the arm I2 is sprung outwardly in a direction normal to the face of the cam II, and when the terminal of the arm I2 rides off the cam II it springs back in the opposite direction. The springing of the arm I2 in a direction normal to the plane of the cam II is used to' rock a pivoted cradle element I6 which carriesI a mercury tube switch Il. When the terminal of the arm I2 is engaging the surface of the cam II, the cradle I6 is tilted so that a circuit is closed through the mercury tube switch Il, and when the terminal of the arm I2 is clear of the cam II, the mercury tube switch II is tilted to a position where its contacts do not close a circuit.

'and which is designated I8.

`.power lines 22 and 23 are wires The construction andarrangement of this cam temperature control unit are fully described and and the longer the mercury tube switch is closed, the longer will be `the, on periods for the heat.

In additionto the cam I I the unit F1 has a second cam which is rotated once every 24 hours As expressed in my copending application, the cam I8 is a heating up cam. It is designed to engage the arm I2 at that -time in the rangeclsimilarly to the mercury tube switch I1.

The mercury tube switch I1 of unit F1 is in series with' the contacts 20 of the day thermo- `stat G1 and the mercury tube switch I1' is in series with the contacts 20 of the night thermo- `stat G2. The arrangementl `is, such that if the mercury tube switch I1 is calling for heat; i. e., has been tilted to a closed position but the room V temperature in which the control panel is housed is such' as to open the contacts stat G1, the circuit through the mercury tube switch I1 will not be completed, and if the room temperature is such that the contacts 20 ofthe night thermostat G2 are open, the circuit through the mercury tube switch I1 cannot be completed.

In the drawing, wires 20 of day thermo- 22 and 23 are the main current supply lines to the system. 24 designates a manual switch in the supply lines. Wires 22' and 23 leading off the supply lines 22 and 23 respectively connect through a manual switch 25 to the motors I6 and IU of the electric clocks for the units F1 and F2 respectively so that the clocks I `and I3 operate `exceptional instance that either of these 4two switches would at any time be open. Another i pair of wires 22a and 23a lead from the wires 22' `and 23 respectively to the clock 26 of the time switch unit T. `The time switch 'I' operates a switch arm 21 at predetermined intervals between 1an on and an 01T position. It is in the on position which is the dotted line position shown in the gure during` the day and in the off position during the night. Connected with the main 28 and 29 which supply the `primary winding of a step-down transformer'30. Alower voltage is used in the control circuit, and the secondary winding of the transformer 33 supplies this lower voltage current through wires 3| and 32. A wire 33 connects with the wire 32 and leads to one contact of the time switch T. The other and back to the transformer. When the 'time switch 21 is open there is of course no current through the relay winding 34 and the armature 35 is pulled away from the field coil 34 by a spring 31.

The armature 35 of the relay is connected to two single pole double throw switches 33 and 39. When the magnet 34 38 closes a circuit with contact 38a and when the `from the day thermostat G1 wire magnet 34 is energized, the contact at 38a is opened and the switch closes a circuit with contact 38h. Likewise, switch arm 39 engages contact 33a when the magnet34 is cle-energized and engages `contact 39h when the magnet 34 is energized.

Contact 38a is connected through wire 40 with switch 4I of the night relay switch S. Contact 39a ofkthe time switch is connected through wire 42 with switch arm 43 of the night relay switch 6. Contact 381) of the time switch is connected through wire 44 terminal 41 of e. change-over switch 48. A wire 49 leading from the contact 41 connects to switch arm 50 of the relay-operated day switch 5 so that there is a circuit from contact 3912 to the switch arm 53. The day switch 5 in'addition to having the two switch' arms 46 and 56 has an armature 5I which is pivotally connected to the two arms 46 and 50 for rocking them. An electromagnet 52 is provided for operating the armature 5I in one'direction while a spring 53 moves the armature in theopposite direction. When the magnet 52 is de-energized, the switch arm 46 engages a switch contact 46a and when the magnet 52 is energized, the switch arm 46 engages Contact 4517. Likewise, switch arm 5D engages switch contact 53a when the relay 52 is cie-energized and engages contact 50h when the magnet 52 is energized.

The two switch arms 4! and 43 oi the night relay 6 are similarly connected with an armature 54 which is moved in one direction by a magnet 55 and in the opposite direction by a spring 56. When the magnet is dra-energized, switch arm 4I engages contact 4Ia and switch arm 43 engages contact 43a. When the magnet 55 is energized, arm 4I engages contact 4Ib, and arm 43 wire 51 to wire 32 leading from one side of the supply current transformer 33. The other side of the electromagnet 52 connects through wire 58 to contact 20 of the day thermostat G1 and 59 leads to the mercury tube switch I 1. From the mercury tube switch I1 the other terminal connects to wire 60 that leads back to wire 3| which connects to the other side of the current transformer 33 .to complete the circuit for magnet 52. The arrangement is such that when the contact 20 of the day is de-energized, the switch thermostat G1 is closed and the outside temperature arm l2 is engaging the arm l! to close the circuit through mercury tube switch ll, the magnet 52 will be energized, but if the circuit is interrupted at either mercury tube switch l1 or contact 28, the magnet 52 will be de-energized.

The magnet 55 of the night relay switch 6 has one side connected through wire 6| to wire 32 leading from one side of the current supply transformer 33. 55 leads through wire 62 to Contact 26 of the night thermostat G2, and from the other side of the thermostat a wire 63 leads from the thermostat switch 2d to mercury tube switch l'i and from mercury tube switch l'i there is a wire fl connecting into the wire (is so that the electromagnet 55 is energized whenever a circuit is comp-leted through contact 253' and mercury tube switch l'i and is broken when either oi these two switches is open.

For each of the valve units controlled by the control panel there is a panel board E, E', etc., having a series of switches. One of these switches is the change-over switch 68 which controls the valve-operating mechanism D' for the valve A. A similar switchtla is in the panel E for controlling the valve A, and if other valves were illustrated, there would be other switches corresponding to the switches 4S and 63a. The contact 33h in addition to being connected through wire d5 with switch contact et is also connected with a contact 41a of switch ida and of any similar switches that would be provided. The change-over switches 48 and 18a are each provided with a switch arm 48', the switches 48 being single pole double throw switches. The switch arm 4S in each case is pivoted to a switch terminal 58".

It should be pointed out that the time switch has a number of switch arms corresponding to the switch arms 38 and 39, the number of these switch arms corresponding to the number of valves to be controlled. The contact 18h of each of the switches 48 and ma connects to one of these switch arms of the time switch, the contact @Bb of switch 48 being connected through wire B5 to the switch arm 39 while the corresponding Contact 48h of switch d8a is connected through wire 555 with the switch arm 3d. Similarly, if there were other valves illustrated and other switch panels with switches corresponding to the change-over switches 458 and 48a, they would be connected to a similar switch member under the control of the main time switch T. Each of the switch panels E and E in addition to having the switches d8a and 48 respectively as described have another single pole double throw switch which may be termed an on and oil switch designated 6'! in the panel on the switch board E and 58 on the panel E. Each switch panel E and also has another single pole double throw switchy designated t!) on switch board E and 10 on switch board E. This last-named switch will be referred to as the automatic-manna switch. The purpose of the automatic-manual switches E9 and li! is to enable the valves controlled by the respective switch boards to operate with the automatic control under the direction of the time-temperature control panel F or to be switched so as to be operated by manual control. The purpose or the switches G1 and ES, termed the on and ci switches,is to enable the heat to be turned on and ofi manually when the automatic-manual switch is set for manual control. The purpose of the change-over The other side of the electromagnet CFL switches t8 and 48a is to enable the valve controlled by the respective switches to operate according to the program established bythe time switch T or to enable any particular valve to be operated according to the day program even though the time switch may be establishing a night heating program for the rest of the building. In addition to the three switches; i. e., the automatic-manual, the on-of and the schedule change-over switch, each of the switch boards E and E has another switch which is referred to as the immediate-heat switch and is designated 'Il in the switch board E and 12 in the switch board E. These switches 'Il and l2 are single pole double throw switches with a clock attachment so that when the switch is moved from one position to another a clock mechanism is wound up which requires a certain number of minutes to unwind and after the lapse of a certain number of minutes, the switch automatically throws back to its original position. In other words they are automatic time switches which are manually moved to one position and remain in that position for only a limited period of time and then automatically restore themselves to the original position. Switches of this character are well known to those skilled in the art and are available on the market and form no part of the present invention per se.

For operating the valve D through the switch board E, wire 3l leading from the current supply transformer 30 is connected to a wire i3 leading to the switch GES. One contact 'M of the switch G9 leads to the immediate-heat switch ll. rEhe switch arm of the immediate-heat switch H normally closes a circuit with contact l5. A wire 'i5 leading from the contact 15 goes to the live terminal of the switch 48 of switch 43a. and this switch is normally set to close the circuit with its contact 48h. As previously explained, the contact 5219 connects through wire t6 with the switch arm 33 of the main time switch T. From switch 33 the circuit may be completed through wire QB to night switch 4i. From switch contact lila of switch 4l there is a wire 'Il connecting to wire 'i8 leading in turn to wire 'FS that contacts with the number 2 terminal of valve-operating mechanism D which is the oi terminal. When the circuit is completed in this manner it will be noted that the magnet Se of the time switch T is de-energized indicating that the automatic control is on' the night schedule. Consequently the circuits are controlled through the night relay 6 and the night relay 6 is shown as being deenergized which means that no heat is called for by the control unit F2 and therefore the circuit has been closed to contact 2 to turn 01T the heat.

If the magnet 55 of the night relay switch is now energized, the circuit will then be completed from switch 33 and contact 33a and wire 4i) to switch arm ll and thence to contact Mb and from contact lill)` through wire 8B and wire Bl, wire 82 to the number I contact of the valveoperating mechanism D which is the on contact. The circuit through the valve-operating mechanism is initially from either contacts l or 2 to contact 4 and from contact 4 through wire 83 to wire 32 to the other side of the current supply transformer 3B.

If the magnet 34 of time switch T had been energized, so that the system was operating on the day schedule instead of on the night schedule, current flowing from the switch contact 48h 'contact 2 which is the setting. If the tenant to the switch 38 would then complete a circuit through contact 38o, wire 45, switch 46, contact 46a, and wire 85 to wire 18 and from wire 19 to off contact, the day relay switch being in the off position. If the mag- Tnet 52 were energized as the circuit would then have been from the switch arm 38 and contact 38o and wire 45 to switch 46 and from switch 46 to contact 46o and thence through Wire 86 to wire 8l and from wire 8l to wire 82 to the on contact terminal I of the valve-operating mechanism D.

The two paragraphs last preceding describe the normal circuits for operating the valve mechanism D under complete Vautomatic control. It may next be assumed that the building is on night schedule when a tenant whose oiiice is controlled by valve A cornes into the building. The building may have been on night schedule for some time and the tenant would want im' mediate heat in the radiators. The night attendant signals the building engineer that immediate heat is required in the zone controlled by valve A whereupon the engineer turns the immediate-heat switch 'H thereby breaking the circuit with contact and closing a circuit with contact 15a. From 15a there is a wire 8l to wire 88 which wire 88 also joins to contact 61a cf the off-on switch 6l. The wire 88 in turn connects to Wire 32 leading to the on contact l of the valve-operating mechanism D for the valve A. thus immediately opening the valve A to supply heat to the zone which the valve A controls and without respect to what the position of the control cams may be. After the heat has been on for a few minutes depending upon the time setting of the switch 1l, the switch will open the cir-v` cuit with contact 15a and again engage contact 'l5 and restore the circuit to a normal automatic expects to remain in the room but a short time, this may be sufficient, but if the tenant expects to occupy the room for a considerable time, it will be desirable to supply more heat than is supplied by the normal night program. In order to do this the change-over switch aim 48 is thrown from engagement with contact 48h to contact 41a. The circuit is then from the automatic switch terminal 'I4 through the` immediate-heat switch 'll to contact 15, to wire 16, to switch arm 43', to contact 47a and thence through wire 89 to wire 45 and day switch 46. As long as the switch 48 stays on the contact dla the valve-operating mechanism D will be under the control of the day switch 5 notwithstanding that the other circuits may remain on the normal night program. Thus it is possible to heat the particular zone supplied by the valve A on the day schedule during the night heating program as long as may be necessary and then throw the valve back onto its night program as soon as the oiiice has been vacated.

. Under certain circumstances it may be necessary or desirable to operate the valve A manually without taking any of the valves in the heating system oii the established program. This is accomplished rst by the contact 74 to the contact 14a. Leading from the contact 14a is a wire 90 leading to the off-on switch 61. If the off-on switch 61 engages the contact 61a, the circuit from contact 14a of the automatic manual switch will be to the switch 61 to the contact 61a to wire 88 to wire 82 and contact l of the valve-operating mechanism D. This will serve to keep the heat turned on as long as this switch setting remains, but if the switch 61 well as the magnet 34 throwing the switch 69 from moving the switch 6l is moved up to engage contact 61h, the circuit will then be through the switch 6l to contact 61o to wire SI, wire 19 and contact 2 of the unit D which is the off contact. By thus manually between the two positions, the heat can be arbitrarily turned on and off quite independently of the automatic mechanism and the automatic control circuits will be entirely ineiiective to make any change in the operation of the valve A and will remain ineffective until the automatic manual switch has been restored to the automatic position, but the other valves in the system will continue to be subject to automatic control. Restoration of the switch 69 to the automatic position renders the manual oli-on switch ineffective.

It has heretofore been pointed out that by energizing the contacts l and 2, the operation of the motor which opens or closes the valve A is merely initiated and that the circuit has to be maintained until the valve has reached a predetermined -position through a maintaining circuit. The maintaining circuit, starting with the contact 3 which is the maintaining contact is connected to the power supply line 3| through wire 92. The other side of the maintaining circuit of course is through the common return wire 83.

For the purpose of showing the building engineer the exact position of any valve at any time, each switch board E, E', etc., is provided with red and green signal lights,`the red light indicating when the heat is on and the green light indicating when the heat is off. On the switch panel E, 63 is the red light and 94 is the green light. One side of each lamp is connected to the current supply line 32. The other side of the red lamp S3 connects through wire 95 with Wire 88 which in turn connects to the on contact wire 82 so that whenever the contact wire 82 is energized, the lamp 93 is also energized. The green lamp 94 has its other side connected through wire 96 to wire 9| which connects to the oil contact wire I9 so that whenever the off "contact I9 is energized, the lamp 84 will be likewise energized.

The switch arm 56 of the day switch 5 corresponds in function to that of the switch arm 416 except that the arm 5l) controls the circuits to the valve-operating unit D instead of D. Since the circuits are otherwise exactly similar to the circuits for the valve-operating mechanism D, it is needless to specifically describe the same as they may be traced in the same way that the circuit for the valve-operating mechanism D may be traced. It should be further pointed out that the day switch 5 would have additional switches and contacts corresponding to 46 and 5i] for each additional valve to be controlled from the main outdoor thermostat control panel. Likewise, in the night relay switch 5 the switch arm 43 corresponds in function to the switch arm 4| and its circuits also pertain to the control of the valveoperating mechanism D. Where an additional valve is included, an additional switch similar to 4I cr i3 would be included. Thus there is one switch such as 33 or 39 in the main time switch T for each valve, there is one switch such as 46 or 58 in the day relay for is one switch similar to 4 relay switch for each valve.

The general operation of the invention may now be followed. There are two program cams Il and Il comprising the heating program unit. Cam H determines the day program and cam Il determines the night program. The cams 6 in conjunction with the temperature responsive arms I2 and E2 control the closing o circuits through switches Il' and ll respectively. The switch il is in series with thermostat G1 and mercury switch il" is in series with night thermostat G2. The cams in conjunction with the therme-stats cause the intermittent energizing and de-energizing of the magnets 52 and E5 respectively of the day and night relay switches. Whether the system responds to the day cam or to the night cam depends in turn upon the time switch T which shiits the control of the system from and to the day and night relay switches 5 and 6. The switches 5 and 6 as well as the time switch T has a separate switch for each source of steam supply to be controlled. Vv'hen he time switchT is set to cause the night switch t to operate, the control unit F2 governs the operation of all of the valve-operating mechanisms D, D', etc., and when the time switch shifts the control to the day relay, the cam unit F1 exercises the control. The control will be automatic as long as the automatic-manual switch (i9 or 'iii for any unit is in the automatic position, but any valve can be selectively put under manual control by throwing the automatic switch for any particular valve to the manual position. Any valve may be thrown under the control of the day cam unit F1 even though the time switch T calls for the night program to be in eirect and the change-over for any one valve does not affect the other valves. Likewise, immediate heating can be supplied to any zone without taking the system ofi the automatic control to temporarily supply heat to a zone requiring it. The changeover from automatic to manual control is effected through the switch GQ cr 'it as the case may be. Manual control is then eiTected through the switch E?? or tl as the case may be. The

change-over from the regular program to a day ii.

program exclusively for any valve is accomplished by the valve S or d8a as the case may be.

The system described introduces a wide flexibility in the use of automatic heating equipment for oiilce and other buildings particularly where there are a number of zones to be controlled from a single outdoor temperature-responsive unit and where diiierent parts of the building have to be temporarily operated on a schedule different from other parte of the building erratically and without reference to any set program, The sys-- tem enables the building to supply heat to the occupied zones of the building according to the times and conditions of occupancy without disturbing the general automatic set-up for control oi the whole building or a part or section of the building where each part or section is sub-divided into several Zones, each part being under a separate outdoor thermostatically controlled unit.

The cams il and il are designed to primarily establish the heating program for the building and the thermostats G1 and G2 are desirable for evening out any inaccuracies that may arise due to the cams being not exactly right for a particular installation. In other words, for production methods of manufacturing standard cams are provided which may very easily be reshaped by the heating engineer, but the re-shaping cannot, without considerable study and experiment, be such as to exactly t the requirements of the building or the portion of the building which the cam units control. If the cams have a tendency to overheat, this will be corrected by the thermostats G1 and G2, but the predetermined thermostat-s do not constitute the primary source of control, The thcrmcstats of course are incapable of turning on the heat unless the switches il or li', as the case may be, are closed. Correction for underheating as well as overheating is provided for through the adjustment of the arms E2 and l with. reference to their cams, as more fully explained in my said copending application. This adjusting mechanism is indicated in the drawing at 9i. The present application is a continuation in part of my said copending application,

While I have used the terms day and night with reference to the cams and thermostats and relay switches, it will be understood that these are merely expressions to indicate alternate periods in which different heating schedules are employed and that the expressions day and nigh are not used in a limiting sense but `rather as a means of distinguishing between periods when diierent schedules of temperatures are maintained. Also, while I have referred to electrically operated valves, this is not by way of limitation and the term valves is intended to include other sources of heat supply susceptible to automatic control by the system herein described.

While I have illustrated and described speciiically only one embodiment of my invention, it will be understood that the invention is not limited to the particular structure and arrangement of the parts disclosed and that it may be otherwise embodied within the scope and contemplation i the following claims.

I claim:

l. A heat control system comprising a time temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maintaining a night heating program, a circuit opening and closing means forming a part of each of said program mechanisms, a plurality of separate electrically operated heat supply valves for supplying heat to diiierent zones of a building,

.. means whereby each of said circuit opening and closing means may control the opening and closing of all the heat supply valves, means including a time switch for rendering the day and night program mechanisms alternately effective over periods of time for controlling the valves, and selectively operable switch means for operating any valve independently of the said program mechanisms and time switch while the remainder of the system is governed by the program mechanisms and time switch.

2. A heat control system comprising a time temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maini taining a night heating program, a circuit opening and closing means forming a part of each of said program mechanisms, a plurality of separate electrically operated heat upply valves for supplying heat to different zo es of a building, means whereby each of said circuit opening and closing means may control the opening and closing of all the heat supply valves, means including a time switch for rendering the day and night program mechanisms alternately elective over predetermined periods of time for controlling the valves, selectively operable switch means for operating any valve independently of the said program mechanisms and time switch while the remainder of the system is governed by the program mechanisms and time switch, and other valves, selectively y each of the circuit 2,301,040` switch means for each valve selectively operable to connect a selected valve into the control circuits so that the day program mechanism controls said valve independently of the said night program mechanism and while the other valve mechanisms remain under the control of said night program mechanism.

3. A heat control system comprising a time temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maintaining a night'heating program, a circuit opening and closing means forming a part of each of said program mechanisms, a plurality of separate electrically operated heat supply valves for supplying heat to different zones of a building, means whereby each of said circuit opening and closing means may control the opening and closing of all the heat supply valves, means including a time switch for rendering the day and night program mechanisms alternately effective over predetermined periods of time for controlling the valves, selectively operable switch means for operating any valve independently of the said program mechanisms and time switch while the remainder of the system is governed by the program mechanisms and time switch, other switch means for each valve selectively operable to connect a selected valve into the control circuits so that the day program mechanism controls said valve independently of the said night program mechanism and while the other valve mechanisms remain under the control of said night program mechanism, and still another selectively operable time switch mechanism for opening the valve to admit steam to the zone controlled by it at any point in the heating program and keeping such valve open for a predetermined limited time and thereafter automatically restoring the circuit to automatic control through one of said program mechanisms and while the circuits for the other valves are unchanged.

4. A heat control system comprising a time temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maintaining a night heating program, a circuit opening and closing means forming a part of each of said program mechanisms, a plurality of separate electrically operated heat supply valves for supplying heat to diiferent zones of a building,

means whereby each of said circuit opening and closing means may control the opening and closing of all the heat supply valves, means including a time switch for rendering the day and night program mechanisms alternately effective over predetermined periods of time for controlling the operable switch means for operating any valve independently of the said program mechanisms and time switch while the remainder of the system is governed by the program mechanisms and time switch, and a separate indoor thermostatic switch in series with closing means of the heating program mechanisms for exercising the secondary control over the heating program mechanisms whereby said circuit closing means are ineffective when the room thermostats are open.

5. A heating system comprising a control unit having a constantly driven cam and means responsive to outside temperaturecooperating with the cam for closing an electric circuit intermittently for periods of time which Vary accordfor each valve anism controlled by said ing to outside temperature, a heat supply mech- `of the night control unit and said circuit, and an immediate-heat control means including a'switch which is manually set and which automatically releases after a predetermined period of time for temporarily operating the heat supply mechanism independently of the control unit and thereafter automatically restoring the heat supply mechanism to operation by the control unit.

6. A heat control system comprising a time temperature control having two heating program mechanisms, each of said mechanisms compris-A ing a cam and a movable arm cooperating with the cam, temperature responsive means for moving the said arm of each mechanism, one of said mechanisms being provided for maintaining a day heating program and the other for maintaining a night heating program, a circuit opening and closing means forming a part of each mechanism, a plurality of separate electrically operated heat supply valves, a day relay switch controlled by the day program mechanism, a night relay switch controlled by the night program mechanism, a control circuit for each valve controlled by both the day switch and the night switch, and a time switch for determining whether the day relay or the night relay controls the operation of the Valves.

7. A heat control system comprising a time temperature control having two heating program mechanisms, each of said mechanisms comprising a cam and a movable arm cooperating with the cam, temperature responsive means for moving the said arm of each mechanism, one of said mechanisms being provided for maintaining a day heating program and the other for maintaining a night heating program, a circuit opening and closing 'means forming a part of each mechanism, a plurality of separate electrically operated heat supply valves, a day relay switch controlled by the day program mechanism, a night relay switch controlled by the 'night program mechanism, a control circuit for each valve controlled by both the day switch and the night switch, a time switch for determining whether the day relay or the night relay controls the operation of the valves, and an indoor thermostatic switch in series with the circuit opening and closing means of the day program mechanism and a night thermostatic switch in series with the circuit opening and closing means program mechanism whereby said thermostats exercise the program mechanisms.

8. A heat control system comprising a central temperature control having two heating program mechanisms one being for maintaining a day taining a night heating program, a circuit opening, and closing means forming a part of each program mechanism, means responsive to outdoor temperature controlling the opening and closing of said means, a plurality of separate electrically operated heat supply valves, circuits day heating program mechanism, a night relay switch operated by the circuit opening and closing means of the night program mechanism, a time switch for alternately transferring control between the day relay and night relay whereby all of the Valves are operated according to a predetermined day and night program and main-- according tc variations in outside temperature, and a separate manually operable means for each electrically operated valve including a change-over switch by means of which any valve may be selectively operated on the day program independently of the time switch and while the other valves of the system remain subject to the control established through the time switch.

9. A heat control system comprising a central temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maintaining a night heating program, a circuit opening and closing means forming a part of each program mechanism, means responsive to outdoor temperature controlling the opening and closing of said means, a plurality of separate electrically operated heat supply valves, circuits whereby each of said opening and closing means may control the operation of the valves, said circuits including a day relay switch operated by the circuit opening and closing means of the day heating program mechanism, a night relay switch operated by the circuit opening and closing means of the night program mechanism, a time switch for alternately transferring control between the day relay and night relay whereby all of the valves are operated according to a predetermined day and night program and according to variations in outside temperature, and a change-over switch for each valve by means of which any valve may be selectively operated on the day program independently of the time switch while the other valves remain subject to the control established through said time switch, said separate switch also including a selectively operable switch for rendering the automatic control circuit ineffective for any valve while the automatic control circuit remains effective as to all of the other valves in the system.

l0. A heat control system comprising a central temperature control having two heating program mechanisms one being for maintaining a day heating program and the other being for maintaining a night heating program, a circuit opening and closing means forming a part of each program mechanism, means responsive to outdoor temperature controlling the opening and closing of said means, a plurality of separate electrically operated heat supply valves, circuits whereby each of said opening and closing means may control the operation of the valves, said circuits including a day relay switch operated by the circuit opening and closing means of the day heating program mechanism, a night relay switch operated by the circuit opening and closing means of the night program mechanism, a time switch for alternately transferring control between the day relay and night relay whereby all of the valves are operated according to a predetermined day and night program and according to variations in outside temperature, and a separate switch for each electrically operated valve, a change-over switch for each valve whereby each valve may be maintained exclusively under the control of the day program mechanism although the system as a whole remains subject to the control established through the main time switch, the central control also comprising an immediate heat control means including a switch which is manually set and automatically restored after a predetermined lapse of time for immediately setting the valve controlled by said switch in an open position irrespective of the program mechanism and without aiecting the other valves governed by the program mechanism and for automatically restoring the valve to control by the program mechanism after a predetermined lapse of time.

l1. A heat control system comprising a plurality of electrically controlled zone heating valves, a single time temperature control for all of said valves for effecting the operation thereof intermittently and for periods of time governed by outside temperature, circuits for controlling the several valves from said control in unison, a separate manual switch for each valve to selectively cause it to be manually controlled independently of the other valves and while the other valves remain under the control of said time temperature control, and a further manual-closing, self-opening switch for each valve for temporarily turning on any valve for a limited period of time only.

12. A heat control system comprising a plurality of electrically controlled Zone heating valves, a time temperature control mechanism for all of said valves for affecting the opening and closing thereof intermittently and for periods of time governed by outside temperature, said control mechanism having day and night control units, a main time switch for alternately rendering the day and night units effective, circuits for controlling the several valves in unison from the said control mechanism and a separate switch for each valve by means of which any valve may be operated exclusively under the control of the day unit, and other switch means by means of which any valve may be selectively controlled independently of the control mechanism and while the other valves remain under the supervision of said control mechanism.

13. A heating system comprising a main control mechanism for establishing a normal heating program and including separate day and night time-temperature responsive circuit closing devices, a plurality of heat supply valves with electric means for operating the same, said valves being under the supervision of the main control mechanism, a time switch to alternately shift the control of the valves between the day and night circuit closing devices of the main control mechanism, and switch means by which any valve may be selectively maintained under the control of the day program device while the other valves remain under the time temperature program as determined by the time switch.

FELIX A. GNTHER. 

